Fall 2010 IAB
September 15 to 17
Preparation and Characterization of Monodisperse Carbon Nanotube Materials and Devices
Large-scale production of high purity carbon nanotubes has the potential to enable or improve many applications . Recently, we have developed a scalable and flexible technique for sorting single-walled carbon nanotubes (SWNTs) by their physical and electronic structure using density gradient ultracentrifugation (DGU) . Diameter-sorted metallic SWNTs yield semi-transparent conductive films with tunable optical absorption . On the other hand, semiconducting SWNTs enable thin film transistors with high switching ratios and drive currents . Most recently, chiral surfactants have been utilized for DGU-based sorting of SWNT enantiomers . In all cases, analytical ultracentrifugation measurements allow the SWNT surfactant loading to be quantified and optimized for improved DGU sorting . This talk will also delineate DGU sorting of double-walled carbon nanotubes (DWNTs). Since DWNTs possess a buoyant density that is intermediate between SWNTs and multi-walled carbon nanotubes, a two-step DGU process has been developed for high purity DWNTs . DGU-sorted DWNTs enable characterization of the fundamental properties of DWNTs and yield high performance transparent conductive films.
 M. C. Hersam, Nature Nanotechnology, 3, 387 (2008).
 M. S. Arnold, et al., Nature Nanotechnology, 1, 60 (2006).
 A. A. Green and M. C. Hersam, Nano Letters, 8, 1417 (2008).
 M. Engel, et al., ACS Nano, 2, 2445 (2008).
 A. A. Green, et al., Nano Research, 2, 69 (2009).
 M. S. Arnold, et al., ACS Nano, 2, 2291 (2008).
 A. A. Green and M. C. Hersam, Nature Nanotechnology, 4, 64 (2009).